New York City has a secret subway line with antique cars — here's what it's like to ride it

The New York City subway system is one of the most fascinating curiosities in a city full of mysteries. Miles of underground track shrouded in darkness, littered with abandoned stations and secret passageways — it's a common object of desire for the urban explorers among us.

And, occasionally, New York City acknowledges the delightful mystery surrounding its 24-hour transportation system. The annual "Shopper's Special" train line is a perfect example of this:

A woman dressed in early 20th-century fashion (while listening to music on her 21st-century smartphone) stands on the annual Shopper's Special subway line.Ben Gilbert/Business Insider

The train line, consisting of eight vintage New York subway cars from several different eras, runs for a few weekends each year — from the Sunday after Thanksgiving to the end of the year, only on Sundays.

So what'd we do this past weekend? We got on the train and took a ride!

I got on at the Second Avenue stop in Manhattan — the train runs between the Second Avenue stop in Manhattan and the Queens Plaza stop in Queens.

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As you can see, the train runs all day starting at 10 a.m. and concluding at about 5 p.m.

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Even though we arrived at 12:30, there were already a bunch of people waiting — some were clearly tourists; others were clearly New Yorkers.

You can tell the difference between tourists and New Yorkers pretty quickly after living here for a while.Ben Gilbert/Business Insider

A ton of people on the train were dressed in period-appropriate clothing. Of note, these are not paid actors.

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The gentleman here in the white hat told me that he and his crew were going to a party afterward at Webster Hall, an event space/concert hall in Manhattan's East Village.

The event at Webster Hall was called the Jazz Age Tea Dance — it's an opportunity for people to dress up as if it's the 1920s, dance to jazz, and drink classic cocktails.Ben Gilbert/Business Insider

But you're here for the train, right? So was I! It arrived about 10 minutes ahead of its 1:03 p.m. departure time — plenty of time for photos!

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Just like any NYC subway, the Shopper's Special rolls into the station at high speed:

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Since the Shopper's Special line runs during the holidays, it's festooned with Christmas wreaths on the back and front:

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While the train was stopped, people dressed in anachronistic clothing posed for photos next to the antique train cars:

Ben Gilbert/Business Insider

There are some amazing details on these old train cars:

Like this whistle!Ben Gilbert/Business Insider

And these air vents!Ben Gilbert/Business Insider

OK, enough is enough: It's time to get on this train and take a ride through history!

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Right off the bat, the level of detail is stunning. Old advertisements run through each car:

The "Subway Sun" was the name of the subway's courtesy campaign in the 1940s. There are echoes of these courtesy signs in today's subway, care of the Metropolitan Transit Authority.Ben Gilbert/Business Insider

Many of the advertisements on the first train car were from the 1940s, such as this advertisement for war bonds:

The "Mighty 7th" war loan advert ran shortly after the Allied victory on the Western front, in May 1945. It's modeled on the Joe Rosenthal photograph of US soldiers raising an American flag in Iwo Jima.Ben Gilbert/Business Insider

The cars are near-perfectly restored, from the metal "straps" to hold onto, to the yellow-orange seats.

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The lightbulbs have all been replaced, and the ceiling fans are all running (pushing air out of the vents along the top of the car).

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This car was built in 1932 by the American Car and Foundry company, so it's assuredly gotten some love in the past 80 years.

This car, and the rest of the cars on the Shopper's Special train line, are usually out of service and on display at the New York Transit Museum.Ben Gilbert/Business Insider

In addition to restoring the lighting and ventilation systems, the MTA also restored the station ID placard. Remember how there weren't always screens everywhere?

Ben Gilbert/Business Insider

A lot of the fun is in the details. I couldn't stop gawking at every old advert, like this adorable Wrigley's ad:

"Chew it after every meal!"Ben Gilbert/Business Insider

And this amazingly inexpensive soap. Just five cents!

Who doesn't want to GLOW with health?Ben Gilbert/Business Insider

There's something inherently more classy about calling it the "City of New York" instead of just New York City, isn't there?

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Nearly 100 years later, and the New York subway is still running ads for New Yorkers (and tourists!) to visit Coney Island.

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Some of the ads are for events long passed, like this "I Am An American Citizenship Day" — an apparently free event in Central Park.

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And yes, Citizenship Day is a real American holiday that you've probably never heard of (I certainly hadn't). It takes place on September 17 every year and serves to commemorate the signing of the US Constitution (on September 17, 1787). The holiday was originally called "I Am An American Day," which was celebrated during the 1940s; it became "Citizenship Day" in the early 1950s. Probably not a bad idea considering America's history as a nation of immigrants.

To the next car! The Shopper's Special keeps the doors between cars open, so you can freely walk through its eight cars:

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The next car was even older, from 1930, also built by American Car and Foundry.

Ben Gilbert/Business Insider

This is not a bathroom — this is for subway operators, despite looking like some sort of nightmare prison:

Ben Gilbert/Business Insider

This MTA worker even dressed the part:

Ben Gilbert/Business Insider

The sliding doors were far less safe on these early trains. If you got caught in between, it felt as if two metal doors were closing on you!

You can even see where the doors slot into the train car walls.Ben Gilbert/Business Insider

Despite the subway car being from the 1930s, advertisements in this car started erring toward the 1960s:

This ad would've run after President John F. Kennedy's assassination on November 22, 1963.Ben Gilbert/Business Insider

This older car looked a bit worse for wear — the metal "straps" were extra worn, and the fans were worryingly close to riders' heads:

Ben Gilbert/Business Insider

The seats have clearly been replaced, but they still retain the same charm of their original form:

There were some adorably bizarre seats on this first car:

Next car!

The next car was far more modern, but that's not because it was built much more recently than the other cars:

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The "straps" were much newer, as was the lighting and the seats. This looked the closest to the modern New York subway:

Ben Gilbert/Business Insider

Check out these futuristic oscillating fans!

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And these "modern" destination placards!

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The subway map looked considerably different back when this train last ran:

Ben Gilbert/Business Insider

These cars ran through the 1970s — some of the riders were discussing when they used to ride on these trains in New York:

Check out this fantastic seat decoration!Ben Gilbert/Business Insider

For the final car, another throwback to the 1930s (though the decoration on the interior is from the 1940s):

Rather than opening a window (as is done now), the train's conductor had to straight-up lean out in between train cars while stopping at stations.Ben Gilbert/Business Insider

Look at this tiny platform he's standing on:

This is on a moving subway car, keep in mind.Ben Gilbert/Business Insider

The final car looked more like a train line than the modern subway system:

Ben Gilbert/Business Insider

It was full of the same adorably designed seats:

Ben Gilbert/Business Insider

And the placards on this one even lit up:

Ben Gilbert/Business Insider

My final look into the train was perfectly representative of the bizarre mash-up of antique train cars with modern life: a woman, dressed in antique clothes, listening to music on her smartphone.

Ben Gilbert/Business Insider

We arrived at the Queens Plaza stop not long after boarding at Second Avenue in Manhattan. Here's the Shopper's Special antique train line as it rides away, with one of the many passengers posing for a final pic:

Ben Gilbert/Business Insider

The Shopper's Special train line runs every Sunday from 10 a.m. to 4 p.m., starting at the Second Avenue stop in Manhattan and completing at the Queens Plaza stop in Queens. It runs along the F/M line, making a handful of stops on the way.

Rides cost the same $2.75 that all subway rides cost, and you can take the train as many times as you'd like. But hurry up and do it sooner rather than later, as this unique subway line runs only through December 18. Check out more info straight from the MTA right here.